Oxford Circus (LU) 1 to Green Park (LU) 1 has a fare of £2.50 and an all day cap of £7.70.
Croxley (LU) 7 to Wartford (LU) 7 has an off-peak fare of £1.60 and an off-peak cap of £14.10.
I know that the fares and caps are what they are. It is nice that Zone 7-to-7 fare is much cheaper than Zone 1-to-1 fare. But I am trying to understand if there is some rationale behind why the Zone 7-to-7 off-peak cap is so much more expensive than the Zone 1-to-1 all day cap?